SMAP1 (stromal membrane-associated protein 1)
2008-03-01 Kenji Tanabe , Shunsuke Kon , Masanobu Satake AffiliationDepartment of Molecular Immunology, Institute of Development, Aging,, Cancer, Tohoku University, Sendai, Japan
DNA/RNA
Description
The gene spans an approximately 190 kb region, and is composed of 11 exons.
Transcription
There is only one transcription initiation site. However, due to alternative splicing, generated are two types of transcripts, isoforms A and B. The length of each transcript is either 3344 (isoform A) or 3263 nt (isoform B). The isoform A retains, and the isoform B lacks in-flame exon 5, respectively.
Proteins
Note
SMAP1 is a member in the ArfGAP protein family.
GAP, an ArfGAP domain; K-rich, a lysine-rich region; CHC, a clathrin heavy chain-binding motif; CALM, a clathrin assembly protein (CALM)-binding domain.
Description
There are two isoform proteins. One translated from an isoform A transcript is constituted by 467, and the other from an isoform B is by 440 aa residues. A protein diagram shown above represents an isoform B type.
Expression
Both isoform transcripts are detected in various human tissues. Expression appears to be almost ubiquitous.
Localisation
SMAP1 protein is detected in the cytoplasm of cells, and appears to be highly concentrated near the plasma membrane.
Function
SMAP1 functions as a GTPase-activating protein for an Arf6 GTPase. Arf6 is a Ras-related, small GTPase, and regulates clathrin-dependent and -independent endocytosis as well as actin dynamics. SMAP1 is specifically involved in the Arf6-regulated, clathrin-dependent endocytosis. This is achieved by direct interaction of SMAP1 with clathrin heavy chain.
Homology
As a highly homologous gene to SMAP1, SMAP2 is identified on 1p34.1-35.3. SMAP1 and SMAP2 constitute a small subfamily in the ArfGAP family. SMAP2 protein is specifically involved in the early endosomes to trans-Golgi network transport.
Implicated in
Entity name
t(6;11)(q13;q23) in acute leukemia.
Note
Two cases have been reported so far.
Disease
One case is from an M4 subtype of acute myeloid leukemia. A type of leukemia is not described for the other case.
Hybrid gene
One leukemia patient possessed the 46, XX, t(6;11)(q13;q23) karyotype. In this patient, reciprocal translocation occured between intron 11 of MLL gene and intron 6 of SMAP1 gene. The chimeric 5-MLL-SMAP1-3 transcript encodes a chimeric MLL-SMAP1 protein.
Fusion protein
MLL-SMAP1
Schematic illustration of chimeric MLL-SMAP1 protein. The authentic MLL and SMAP1 proteins are also shown.
AT hook, an AT-hook domain; NLS, a nuclear localization signal; MT, a methyltransferase domain; PHD, a plant homeodomain zinc finger; BROMO, a bromo domain; SET, a su(var)3-9, enhancer-of-zeste, trithorax domain. GAP, an ArfGAP domain; K-rich, a lysine-rich region; CHC, a clathrin heavy chain-binding motif; CALM, a clathrin assembly protein (CALM)-binding domain.
Article Bibliography
| Pubmed ID | Last Year | Title | Authors |
|---|---|---|---|
| 9593286 | 1998 | Ten novel 11q23 chromosomal partner sites. European 11q23 Workshop participants. | Harrison CJ et al |
| 12119110 | 2002 | Cloning, characterization and chromosome mapping of the human SMAP1 gene. | Marcos I et al |
| 15626757 | 2005 | Diagnostic tool for the identification of MLL rearrangements including unknown partner genes. | Meyer C et al |
| 16571680 | 2006 | SMAP2, a novel ARF GTPase-activating protein, interacts with clathrin and clathrin assembly protein and functions on the AP-1-positive early endosome/trans-Golgi network. | Natsume W et al |
| 16805823 | 2006 | Involvement of a novel ADP-ribosylation factor GTPase-activating protein, SMAP, in membrane trafficking: implications in cancer cell biology. | Tanabe K et al |
| 15659652 | 2005 | A novel GTPase-activating protein for ARF6 directly interacts with clathrin and regulates clathrin-dependent endocytosis. | Tanabe K et al |
Other Information
Locus ID:
NCBI: 60682
MIM: 611372
HGNC: 19651
Ensembl: ENSG00000112305
Variants:
dbSNP: 60682
ClinVar: 60682
TCGA: ENSG00000112305
COSMIC: SMAP1
RNA/Proteins
Expression (GTEx)
Pathways
| Pathway | Source | External ID |
|---|---|---|
| Endocytosis | KEGG | ko04144 |
| Endocytosis | KEGG | hsa04144 |
Protein levels (Protein atlas)
References
| Pubmed ID | Year | Title | Citations |
|---|---|---|---|
| 36494580 | 2023 | Pals1 functions in redundancy with SMAP1 to inhibit Arf6 in order to prevent Rac1-dependent colorectal cancer cell migration and invasion. | 0 |
| 36494580 | 2023 | Pals1 functions in redundancy with SMAP1 to inhibit Arf6 in order to prevent Rac1-dependent colorectal cancer cell migration and invasion. | 0 |
| 28011674 | 2017 | Rare genetic variants in SMAP1, B3GAT2, and RIMS1 contribute to pediatric venous thromboembolism. | 8 |
| 28011674 | 2017 | Rare genetic variants in SMAP1, B3GAT2, and RIMS1 contribute to pediatric venous thromboembolism. | 8 |
| 23752192 | 2014 | Involvement of small ArfGAP1 (SMAP1), a novel Arf6-specific GTPase-activating protein, in microsatellite instability oncogenesis. | 0 |
| 25281535 | 2014 | The Arf GTPase-activating protein SMAP1 promotes transferrin receptor endocytosis and interacts with SMAP2. | 6 |
| 23752192 | 2014 | Involvement of small ArfGAP1 (SMAP1), a novel Arf6-specific GTPase-activating protein, in microsatellite instability oncogenesis. | 0 |
| 25281535 | 2014 | The Arf GTPase-activating protein SMAP1 promotes transferrin receptor endocytosis and interacts with SMAP2. | 6 |
| 15659652 | 2005 | A novel GTPase-activating protein for ARF6 directly interacts with clathrin and regulates clathrin-dependent endocytosis. | 32 |
| 15659652 | 2005 | A novel GTPase-activating protein for ARF6 directly interacts with clathrin and regulates clathrin-dependent endocytosis. | 32 |
Citation
Kenji Tanabe ; Shunsuke Kon ; Masanobu Satake
SMAP1 (stromal membrane-associated protein 1)
Atlas Genet Cytogenet Oncol Haematol. 2008-03-01
Online version: http://atlasgeneticsoncology.org/gene/42974/smap1-(stromal-membrane-associated-protein-1)
